Shearer anti-collision

ABSTRACT

Systems and methods for operating a mining machine. One system includes a roof support system, a radar device, and at least one controller. The roof support system incorporates an anti-stealth device, and the radar device is configured to transmit a plurality of radio waves toward the roof support system and detect a plurality of reflections of the plurality of radio waves. The at least one controller is configured to obtain reflection data from the radar device representing timing information regarding the plurality of radio waves and the plurality of reflections, determine a position of the roof support system based on the reflection data, and perform at least one automatic action when the identified position of the roof support system satisfies a threshold.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Nos. 61/871,576, 61/871,581, 61/871,583, and 61/871,586, each filed Aug. 29, 2013. The entire content of each provisional application is hereby incorporated by reference.

BACKGROUND

Embodiments of the invention relate to methods and systems for detecting objects around mining equipment, such as a longwall shearer.

SUMMARY

Collisions between mining equipment can cause costly damage to the mining equipment. Accordingly, embodiments of the invention provide systems and methods for detecting objects located around mining equipment, such as a longwall shearer. The detected objects can include a roof support system. For example, a non-contacting distance sensor, such as a radar sensor, can be used to detect the distance between the longwall shearer and at least one portion of a roof support system, such as a canopy, a leg, and/or a sprag. One or more automatic actions can be performed depending on the detected distance (e.g., to prevent or mitigate a collision).

In particular, one embodiment of the invention provides a system for operating a mining machine. The system includes a roof support system, a radar device, and at least one controller. The roof support system incorporates an anti-stealth device. The radar device is configured to transmit a plurality of radio waves toward the roof support system and detect a plurality of reflections of the plurality of radio waves. The at least one controller is configured to obtain reflection data from the radar device representing timing information regarding the plurality of radio waves and the plurality of reflections, determine a position of the roof support system based on the reflection data, and perform at least one automatic action when the identified position of the roof support system satisfies a threshold.

Another embodiment of the invention provides a method of operating mining equipment. The method includes transmitting a radio wave in a direction of travel of a miner, receiving a reflection of the radio wave from a corner cube reflector positioned on a roof support system, and determining, with at least one controller, a position of the corner cube reflector based on the reflection of the radio wave. The method also includes modifying operation of at least one selected from the group comprising the miner and the roof support system based on the position.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates mining equipment.

FIG. 2 schematically illustrates mining equipment.

FIG. 3 schematically illustrates a controller for the mining equipment of FIGS. 1 and 2.

FIG. 4 is a flowchart illustrating a method performed by the controller of FIG. 3.

FIG. 5 graphically illustrates a region-of-interest filter applied by the controller of FIG. 3.

FIGS. 6A-6B illustrate undulation and bends in a conveyor system.

FIGS. 7A-7B illustrate a radar device mountable on mining equipment according to one embodiment of the invention.

FIGS. 8A-8C illustrate the radar device of FIGS. 7A-7B mounted on a longwall shearer according to one embodiment of the invention.

FIG. 9 illustrates an anti-stealth device.

FIG. 10 schematically illustrates a corner cube reflector.

FIG. 11 illustrates an anti-stealth device attached to a roof support system.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the methods, operations, and sequences described herein can be performed in various orders. Therefore, unless otherwise indicated herein, no required order is to be implied from the order in which elements, steps, or limitations are presented in the detailed description or claims of the present application. Also unless otherwise indicated herein, the method and process steps described herein can be combined into fewer steps or separated into additional steps.

In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. Also, electronic communications and notifications may be performed using any known means including direct connections, wireless connections, etc.

It should also be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be used to implement the invention. In addition, it should be understood that embodiments of the invention may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processors. As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. For example, “controllers” described in the specification can include one or more processors, one or more non-transitory computer-readable medium modules, one or more input/output interfaces, and various connections (e.g., a system bus) connecting the components.

Longwall mining equipment comprises of a number of individual structures that are connected together and/or move relative to each other in sequence. In particular, as illustrated in FIG. 1, the equipment includes a longwall shearer 10 that cuts material, such as coal, from a cutting face 12. The longwall shearer 10 can include a mobile cutting machine that includes at least two cutter drums (an upper drum 11 a and a lower drum 11 b).

The shearer 10 is mounted on and moves along a conveyor system 14. Material cut by the shearer 10 is also loaded onto the conveyor system 14. The conveyor system 14 can include an armored flexible conveyor that has a length approximately equal to the width of the cutting face 12. The conveyor can include a series of steel pans that are able to move relative to each other by flexing. Cut material (e.g., coal) is conveyed on the conveyor by steel bars arranged at approximately 90° to the length of the conveyor, which are moved by a pair of endless chains.

In some embodiments, the conveyor system 14 moves cut material away from the shearer 10 to a delivery point at the end of the conveyor system 14. At this point, conveyed material is transferred to a beam stage loader 15 located in a pre-driven roadway (i.e., a maingate roadway opposite a tailgate roadway).

A powered roof support system 17 is also used with the shearer 10. The roof support system 17 includes a plurality of roof structures or supports 18 positioned side-by-side. Individual roof supports 18 can be advanced (e.g., after the shearer 10 passes) to support a roof above the cutting face 12. For example, in some embodiments, each roof support 18 includes a steel base 18 a. Two or more vertical hydraulic rams 18 b (sometimes referred to as “legs”) extend from the steel base 18 a and support a canopy 18 c (see FIG. 2). The canopy 18 c can be manufactured from steel and is designed to be positioned parallel to and in contact with the roof. A controller can be used to manually and/or automatically move each roof support structure 18 (i.e., each canopy 18 c using the hydraulic rams 18 b). In some embodiments, each roof support structure can be retracted (i.e., not advanced), partially advanced, or fully advanced.

For example, as the shearer 10 moves along the cutting face 12 removing material, a roof is exposed and needs to be supported by advancing each roof support 18 in sequence (e.g., sequentially following a direction of travel of the shearer 10). Prior to advancing, the canopy 18 c of a roof support 18 extends to within approximately 400 millimeters of the upper drum 11 a of the shearer 10, which is typically approximately 1,000 millimeters wide. To support newly exposed roof, each roof support 18 can be advanced by approximately 1,000 millimeters, which means that the canopy 18 c of an advanced roof support 18 is approximately 700 millimeters into the path of the upper drum 11 a. When a roof support 18 is advanced in sequence, the upper drum 11 a has already passed the roof support 18, and, prior to the next pass of the shearer 10, the conveyor system 14 is pushed forward (e.g., by approximately 1,000 to millimeters) to regain an original clearance for the upper drum 11 a from the advanced support 18 (e.g., approximately 400 millimeters). Therefore, when advanced in sequence, roof supports 18 do not generally pose a collision risk for the shearer 10.

However, under certain conditions, one or more roof supports 18 are operated out of sequence (e.g. to provide additional support for an unstable roof). In this context “out of sequence” can mean that a roof supports 18 are advanced (e.g., partially-advanced or fully-advanced) out of order as compared to a normal or routine sequence (e.g., sequentially). Accordingly, in some situations, a roof support 18 is advanced before the shearer 10 passes and the “out of sequence” roof support 18 can be a collision hazard for the shearer 10 (e.g., the upper drum 11 a).

Also, there are circumstances where the clearance distance between an un-advanced roof support 18 and the shearer 10 is less than a minimum distance (e.g., approximately 400 millimeters). For example, there can be steps in the floor of the mine. When the conveyor system 14 is applied to these steps, the “pitch angle” of the conveyor system 14 is changed. Also, because the shearer 10 travels along the conveyor system 14, the pitch angle of the conveyor system 14 is transferred to the shearer 10. Accordingly, the pitch angle of the conveyor system 14 can change the orientation of the shearer 10, which can create collision risks for the shearer 10. In particular, creation of a positive pitch angle in the conveyor system 14 can cause the shearer 10 to tip back toward the roof support system 17 as the shearer 10 traverses the cutting face 12. For example, because a height of a coal face (as usually determined by the thickness of the coal seam) can be up to approximately 6,000 millimeters, a pitch angle of approximately 4° or more can eliminate the minimum clearance distance between the shearer 10 and the roof support system 17 and, consequently, create collision risks.

Similarly, if the roof support system 17 fails or malfunctions (e.g., a hydraulic circuit fault occurs), canopies 18 c of one or more roof supports 18 may be positioned lower than the roof, which creates a situation where the shearer 10 may collide with the supports 18. Also, if the shearer 10 is not controlled properly when creating the roof, the canopies 18 c of the supports 18, once advanced, may have a reduced clearance with respect to the shearer 10. Also, in some embodiments, the powered roof support system 17 includes one or more sprags 19. Sprags 19 extend from the face side of the roof supports 18 (i.e., the canopies 18 c) toward the cutting face 12 under circumstances where additional support needs to be provided (e.g., where the coal seam is thick and slabs of coal may breakaway and fall over like a wall towards the conveyor system 14 and a walkway 22 (see FIG. 2) between the conveyor system 14 and the roof support system 17). For example, in some embodiments, sprags 19 are deployed when the thickness of material (e.g., coal) being mined exceeds approximately 3.5 meters. Sprags 19 can also be used during maintenance activities (e.g., to provide protection to individuals carrying out maintenance activities on the equipment). The sprags 19 can be deployed by small rams, which if faulty or deployed at the wrong time, can position a sprag in a position where the shearer 10 may collide with the sprag 19.

Accordingly, in some embodiments, a shearer automation system (e.g., installed on the shearer 10) can include an autonomous anti-collision subsystem that uses radar (“Radio Detection And Ranging”). Radar technology works on the basis of detecting the reflection of a radio wave, signal, or beam generated by a radar device from structures located around the radar device. A radar device can include a transmitter configured to generate a radio wave and a sensor configured to detect a radio wave. As described in more detail below, the time between transmitting the wave and detecting a reflection of the wave can be used to determine the distance between the radar device and the object reflecting the wave.

Accordingly, the anti-collision subsystem can include a controller configured to receive timing information relating to radio wave transmissions and detections collected by the radar device and determine potential collisions risks. Collisions risks for the shearer 10 can include, but are not limited to, a canopy 18 c of a roof support 18 (e.g., a low canopy 18 c as compared to other canopies 18 c), legs 18 b of the roof support system 17 (e.g., legs 18 b encroaching on the walkway 22 provided between the conveyor system 14 and the roof support system 17), and sprags 19.

For example, FIG. 3 schematically illustrates a controller 28 included in the anti-collision subsystem. As illustrated in FIG. 3, the controller 28 includes a processing unit 30 (e.g., a microprocessor, application specific integrated circuit, etc.), non-transitory computer-readable media 32, and an input/output interface 34. The computer-readable media 32 can include random access memory (“RAM”) and/or read-only memory (“ROM”). The input/output interface 34 transmits and receives information from devices external to the controller 28, such as a radar device 36 (e.g., over one or more wired and/or wireless connections). The controller 28 can also use the input/output interface 34 to communicate with other controllers, such as a roof support controller, a shearer controller, etc.

The processing unit 30 receives information (e.g., from the media 32 and/or the input/output interface 34) and processes the information by executing one or more instructions or modules. The instructions or modules are stored in the computer-readable media 32. The processing unit 30 also stores information (e.g., information received through the input/output interface 34 and/or information generated by instructions or modules executed by the processing unit 30) to the media 32. It should be understood that although only a single processing unit, input/output interface, and computer-readable media module are illustrated in FIG. 3, the controller 28 can include multiple processing units, memory modules, and/or input/output interfaces.

The instructions stored in the computer-readable media 32 provide particular functionality when executed by the processing unit 30. In general, the instructions, when executed by the processing unit 30, identify potential collision risks between mining equipment and perform one or more actions to mitigate or prevent such collisions. For example, the controller 28 can execute the instructions stored in the computer-readable media 32 to perform the method 40 illustrated in FIG. 4. The method 40 includes obtaining reflection data from the radar device 36 (at block 42). The reflection data can include timing information regarding radio waves transmitted by the radar device 36 and corresponding reflections detected by the radar device 36. It should be understood that in some embodiments in addition to obtaining data from the radar device 36, the controller 28 can be configured to provide data to the radar device 36. For example, the controller 28 can be configured to provide control signals to the radar device 36 (e.g., to turn the radar device 36 on and off, to modify operating parameters of the radar device 36, and/or to modify a physical position and/or orientation of the radar device 36).

In some embodiments, the radio wave generated by the radar device 36 reflects from many different materials, including steel, coal, and individuals. Also, the range of the radio wave can be approximately 200 meters. However, some detected objects within this range may not be considered potential collision hazards. For example, in some embodiments, only roof supports 18 that are no more than two supports 18 ahead of the position of the shearer 10 (e.g., the upper drum 11 a) in the current direction of travel of the shearer 10 are considered potential collision hazards. Also, in some situations, an operator can be legitimately positioned between a shearer and a roof support 18 ahead of the shearer 10 in the current direction of travel of the shearer 10.

Accordingly, the controller 28 can be configured to filter the reflection data to identify those reflections associated with a region of interest (“ROI”). For example, as illustrated in FIG. 5, a radar device 36 can be configured to detect a radio wave having a maximum possible angle and a minimum possible angle (e.g., approximately 13° and approximately −13°, respectively) (see A and E in FIG. 5) from a neutral or horizontal axis (see D in FIG. 5). Within this range of possible angles, a maximum ROI angle and a minimum ROI angle can be defined (see B and C in FIG. 5). Accordingly, the controller 28 can be configured to process only reflections detected between the maximum ROI angle and the minimum ROI to identify potential collision hazards. The controller 28 can be configured with different ROI angle ranges for different applications (e.g., different positions of the controller 28 and/or the radar device 36, different types of equipment, different equipment configurations, different mine conditions, etc.), which allows the controller 28 to accurately identify true collision risks.

For example, depending on the nature of material being mined (e.g., coal) it is not uncommon for the conveyor system 14 to undulate and bend (see, e.g., FIGS. 6A-B). Although the conveyor system 14 is specifically designed to accommodate such undulation or bending, the radar device 36 may detect one or more roof supports 18 as being potential collision hazards in these situations when, in reality, the supports 18 are not hazards because bends in the conveyor system 14 ahead of the shearer 10 in its current direction of travel cause the shearer 10 to slew and miss the roof support 18. Accordingly, the controller 28 can be configured with a ROI as described to avoid falsely identifying these roof supports as collision risks.

Furthermore, in some embodiments, the shearer 10 can include an inertial navigation sensor (“INS”). The INS measures the profile of the conveyor system 14 in one or more dimensions. Accordingly, the controller 28 can be configured to receive information from the INS and use the received information to identify any undulations or bends in the conveyor system 14 ahead of the shearer 10 in its current direction of travel. Therefore, the controller 28 can use input derived from the INS in addition or as an independent of an ROI to better judge whether potential collision risks detected by the radar device 36 are genuine or false.

In addition and/or alternatively, the controller 28 can be configured to apply a signal strength filter to the reflection data to identify reflections from different surfaces or materials (e.g., metallic surfaces versus non-metallic surfaces). For example, the controller 28 can be configured to identify whether a detected reflection has a signal strength satisfying a predetermined threshold or range (e.g., associated with reflections from metallic surfaces). In some embodiments, the controller 28 can use multiple thresholds or ranges of signal strengths to identify reflections originating from a plurality of different surfaces (e.g., from individuals, the cutting face 12, steel, etc.).

Accordingly, the ROI filter and/or the signal strength filter can be used to discriminate between potential collision hazards and other objects (currently considered not hazards). For example, in one embodiment, the radar device 36 can be positioned approximately 6 meters from the end of the shearer 10, and the controller 28 can be configured to ignore all reflections from non-metallic surfaces within approximately 6 meters from the radar device 36, as these reflections may be from operators working in a safe zone. Similarly, as another example, the radar device 36 can be positioned at a predetermined angle to detect sprags 19, and the controller 28 can be configured to ignore reflections from the cutting face 12 and only process reflections from steel (i.e., sprags 19). As yet another example, the radar device 36 and/or controller 28 can be configured to detect roof supports 18 relative to a nominal thickness of the coal seam to detect roof supports 18 that are set low.

FIGS. 7A-B illustrate dimensions of the radar device 36 according to one embodiment of the invention. It should be understood that in some embodiments, the radar device 36 and the controller 28 are formed as an integrated device. In other embodiments, these components are separate devices. Also, FIGS. 8A-C illustrate the positioning of the radar device 36 of FIGS. 7A-B on a surface of the shearer 10 according to one embodiment of the invention. As illustrated in FIG. 8C (illustrating detail A as marked in FIG. 8B), in the configuration illustrated in FIGS. 8A-C, the radar device 36 can be mounted at approximately 13° from an upper surface of the shearer 10. In this configuration, the controller 28 can filter reflection data to identify those reflections originating from objects located greater than approximately 6 meters and less than approximately 10 meters from the radar devices that have an angle greater than approximately 0° and less than approximately 13°, and have a signal strength greater than approximately 70 dB (representing metallic surfaces). Accordingly, as illustrated in FIG. 8C, the controller 28 can use these filtering parameters to ignore reflections from roof supports 18 positioned in a normal or expected position (see the three leftmost roof supports 18) while detecting a roof support 18 advanced out of sequence (see the rightmost roof support 18).

In some embodiments, although reflections from metallic surfaces of the roof support system 17 and other metallic components are detectable, the effectiveness of radar in any application can be increased if an anti-stealth device is used that reflects a radio wave back to the radar device 36 in a predictable and efficient manner. For example, in one embodiment, a corner cube reflector 50 (see, e.g., FIG. 9) can be deployed as a target for radio waves generated by the radar device 36. As illustrated in FIG. 10, an incident beam striking a corner cube reflector 50 goes through a series of internal reflections and leaves the reflector 50 in the opposite direction from which it came (i.e., back toward the radar device 36). Accordingly, corner cube reflectors 50 are often referred to as “boomerang reflectors.” Incorporating a corner cube reflector 50 into mining equipment, such as the roof support system 17, at one or more strategic location increases the accuracy of the radar device 36 and the associated anti-collision functionality performed by the controller 28. In particular, the controller 28 can be configured to identify reflections from a corner cube reflector 50 (i.e., reflections returning in the direct opposite direction they were transmitted) to better identify those reflections associated with true potential collision hazards (e.g., particular mining equipment or portions thereof).

In some embodiments, corner cube reflectors 50 can be attached to or incorporated into (i.e., manufactured as part of the structure of) roof support legs 18 b, roof support canopies 18 c, and/or roof support sprags 19. For example, FIG. 11 illustrates a side of a roof support canopy 18 c including a corner cube reflector 50 (e.g., fitted in a recess of a canopy tip). In other embodiments, the corner cube reflector 50 can be added to a piece of mining machinery as an after-market addition. However, creating the corner cube reflector 50 as part of the fabrication of the equipment can provide robustness for mining environments. It should be understood that although corner cube reflectors 50 are described and illustrated in the present application, other types of anti-stealth devices can be used to improve radar detection accuracy.

Returning to FIG. 4, after obtaining the reflection data and optionally filtering the reflection data as described above (e.g., ROI, INS, signal strength, corner cube reflections, etc.), the controller 28 uses the reflection data to determine a position of one or more objects detected around the radar device 36 (at block 60). It should be understood that the filtering and processing of the reflection data as described in the present application can be distributed in various configurations between the radar device 36 and the controller 28. For example, in some embodiments, the radar device 36 provides raw timing data to the controller 28 and the controller 28 performs the filtering and the processing. In other embodiments, the radar device 36 is configured to perform at least some of the filtering and processing prior to providing data to the controller 28.

As noted above, the time between transmitting a wave and detecting a reflection of the wave can be used to determine the distance between the radar device 36 and the object reflecting the wave and hence, a position of the object in terms of a distance from the radar device 36 (e.g., “X” millimeters from the radar device 36). Similarly, knowing the position of the radar device 36 relative to particular mining equipment (e.g., the shearer 10), the controller 28 can use the determined distance between the radar device 36 and the detected object to determine a position of the detected object relative to the particular mining equipment (e.g., “X” millimeters from a cutter drum). Furthermore, based on known mining environment dimensions, an absolute position of the object reflecting a radio wave can be determined (e.g., in longitude/latitude positions, a three-dimensional position, or other geographical position).

After determining a position of at least one object, the controller 28 compares the position to a predetermined threshold (e.g., a distance threshold or range) to determine whether the detected object poses a potential collision risk (at block 62). When the determined position satisfies the threshold (e.g., falls below the distance threshold or falls within the range), the controller 28 performs one or more automatic actions (at block 64). The automatic actions can include issuing a warning (e.g., a visual warning, an audible warning, a tactile warning, or a combination thereof) and/or modifying operation of one or more pieces of mining equipment. It should be understood that in some embodiments, the controller 28 can be configured to apply different thresholds to determine what action to perform. For example, the controller 28 can be configured to issue a warning when a potential collision hazard is within a predetermined “warning” distance from the shearer 10 and stop the shearer 10 when the hazard is within a predetermined “stop” distance from the shearer 10. Also, in some embodiments, the controller 28 is configured to perform at least one automatic action based on a type of a potential collision hazard. For example, if, based on the reflection data, the controller 28 identifies a detected object as a low canopy 18 c (e.g., based on the position of the detected object), the controller 28 can perform a first action. However, if the controller 28 identifies a detected object as an extended sprag 19, the controller 28 can perform a second action different from the first action.

When used to detect collisions between the shearer 10 and the roof support system 17, the controller 28 can be configured to automatically stop or slow the shearer 10 when a potential collision is detected (e.g., an “out-of-sequence” roof support 18). Alternatively or in addition, the controller 28 can be configured to modify operation of the roof support system 17 to move the “out of sequence” roof support 18 (e.g., retract the support 18).

To perform the automatic action(s), the controller 28 can be configured to communicate with one or more controllers for the mining machine equipment (e.g., through the input/output interface 34 using a wired and/or wireless connection). For example, the controller 28 can be configured to send control signals to a speaker or display (on the shearer 10 or remote from the shearer 10). Similarly, the controller 28 can be configured to send control signals to a controller for the shearer 10 and/or the roof support system 17 that manage movement of the shearer 10 and/or the roof support system 17. The control signals instruct the controller(s) how to move the shearer 10 and/or the roof support system 17. In other embodiments, however, the controller 28 can be integrated into these devices. In some embodiments, the controller 28 can also be configured to communicate with other devices to obtain operating conditions that the controller 28 can use to identify whether an automatic action should be generated (e.g., is the shearer 10 moving, what direction is the shearer 10 traveling in, INS information, fault information, etc.).

In some embodiments, the controller 28 can also be configured to provide feedback to at least one operator based on the process reflection data (e.g., regardless of whether the controller 28 performs any automatic actions). For example, the controller 28 can be configured to provide visual information to an operator through a user interface. The user interface can display reflection data and/or objects detected based on the reflection data. The user interface can also display filtering parameters applied by the controller 28. In some embodiments, the operator can use the user interface to modify operation of the controller 28 (e.g., change filtering parameters, initiate one or more automatic actions, change automatic action thresholds and/or ranges, etc.). Optionally, the operator can also use the user interface to override an automatic action performed by the controller 28.

It should be understood that the functionality performed by the controller 28 as described in the present application can be distributed among multiple controllers and/or devices (including, for example, the radar device 36). As noted above, it should also be understood that the controller 28 and the radar device 36 can be combined as an integrated device or can be provided as separate devices on the same or different pieces of equipment. For example, in one embodiment, the controller 28 and the radar device 36 are part of the shearer 10. In other embodiments, the radar device 36 is included on the shearer 10 and the controller 28 is included on a separate device. In still other embodiments, the controller 28 is included in the shearer 10 and the radar device 36 is installed on the roof support system 17 (e.g., each roof support 18 includes its own radar device 36 that can be used to determine a position of the shearer 10). Furthermore, in some embodiments, the radar device 36 and/or the controller 28 is installed on a device configured to move with the shearer 10 (e.g., along the conveyor system 14, such as ahead of the shearer 10 in its current direction of travel). In this situation and other situations, multiple radar devices 36 can be used. For example, one radar device 36 can be used to determine a position of the shearer 10 and/or a specific portion of a shearer 10 (e.g., one of the cutting drums) and a second radar device 36 can be used to determine a position of the roof support system 17. It should also be understood that the anti-stealth devices described herein can be mounted on any piece of mining equipment and is not limited being used with the roof support system 17.

Thus, embodiments of the invention provide methods and systems for using radar to detect objects in a travel path of a shearer. As described above, the detected obstacles can include roof supports advanced “out of sequence,” support canopies that are too low, sprags, and situations where the shearer is tilted relative to the roof supports due to poor control of the shearer. The systems and methods can use reflections from anti-stealth devices incorporated into objects positions around a radar device to increase the accuracy of detecting the objects. When a detected object poses a potential collision risk, one or more automatic actions can be performed including issues warnings and modifying operation of the shearer and/or the detected object.

Various features and advantages of the invention are set forth in the following claims. 

What is claimed is:
 1. A system for operating a mining machine, the system comprising: a roof support system incorporating an anti-stealth device; a radar device configured to transmit a plurality of radio waves toward the roof support system and detect a plurality of reflections of the plurality of radio waves; and at least one controller configured to obtain reflection data from the radar device representing timing information regarding the plurality of radio waves and the plurality of reflections, determine a position of the roof support system based on the reflection data, and perform at least one automatic action when the identified position of the roof support system satisfies a threshold.
 2. The system of claim 1, wherein the anti-stealth device includes a corner cube reflector.
 3. The system of claim 1, wherein the anti-stealth device is incorporated into a canopy of the roof support system.
 4. The system of claim 1, wherein the anti-stealth device is incorporated into a leg of the roof support system.
 5. The system of claim 1, wherein the anti-stealth device is incorporated into a sprag of the roof support system.
 6. The system of claim 1, wherein the radar device is mounted on a surface of a miner.
 7. The system of claim 1, wherein the radar device is mounted on a device configured to travel along a conveyor system separate from a miner.
 8. The system of claim 1, wherein at least one controller is further configured to filter the reflection data to identify at least one of the plurality of reflections originating from an object located more than approximately 6 meters from the radar device and less than approximately 10 meters from the radar device.
 9. The system of claim 1, wherein the at least one controller is further configured to filter the reflection data to identify at least one of the plurality of reflections having an angle within a predetermined range of angle.
 10. The system of claim 1, wherein the at least one controller is further configured to filter the reflection data to identify at least one of the plurality of reflections having a signal strength greater than a predetermined threshold.
 11. The system of claim 1, wherein the at least one controller is further configured to obtain information from an inertial navigation sensor associated with a miner and determine the position of the roof support system based on the reflection data and the information from the inertial navigation sensor.
 12. The system of claim 1, wherein the anti-stealth device is formed into a structure of the roof support system.
 13. A method of operating mining equipment comprising: transmitting a radio wave in a direction of travel of a miner; receiving a reflection of the radio wave from a corner cube reflector positioned on a roof support system; determining, with at least one controller, a position of the corner cube reflector based on the reflection of the radio wave; modifying operation of at least one selected from the group comprising the miner and the roof support system based on the position.
 14. The method of claim 13, further comprising filtering the reflection of the radio wave to determine if the reflection originated from an object located more than approximately 6 meters from the miner and less than approximately 10 meters from the miner.
 15. The method of claim 13, further comprising filtering the reflection of the radio wave to determine if the reflection has an angle within a predetermined range of angle.
 16. The method of claim 13, further comprising filtering the reflection of the radio wave to determine if the reflection has a signal strength greater than a predetermined threshold.
 17. The method of claim 13, further comprising obtaining information from an inertial navigation sensor associated with a miner, wherein modifying the operation includes modifying operation of at least one selected from the group comprising the miner and the roof support system based on the position and the information obtained from the inertial navigation sensor.
 18. The method of claim 13, further comprising transmitting a second radio wave at the miner, receiving a reflection of the second radio wave from the miner, and determining a position of the miner based on the reflection of the second radio wave, wherein modifying the operation includes modifying operation of at least one selected from the group comprising the miner and the roof support system based on the position of the corner cube reflector and the position of the miner. 